Caption: US astronaut Thomas Stafford training. US astronaut Thomas Stafford (born 1930, left) training with veteran Soviet cosmonaut Andriyan Nikolayev (1929-2004, right) inside a Soviet Soyuz spacecraft simulator. Stafford was the commander of the Apollo spacecraft during the Apollo-Soyuz Test Project mission of July 1975. It was Stafford's fourth and last space mission and the first joint US-Soviet mission. Nikolayev flew on the Vostok 3 and Soyuz 9 spaceflights.